Current Pharmaceutical Design - Volume 19, Issue 24, 2013

The development of locomotor function in terrestrial higher vertebrates takes place during both the embryonic period and the first days (or weeks, depending on the species) of postnatal life. It relies on the maturation of different elements such as musculoskeletal system, sensory systems, network connectivity, and neuronal intrinsic properties. This maturation results from the interplay between genetic determinants and ac Read More

Male sexual responses are reflexes mediated by the spinal cord and modulated by neural circuitries involving both the peripheral and central nervous system. While the brain interact with the reflexes to allow perception of sexual sensations and to exert excitatory or inhibitory influences, penile reflexes can occur despite complete transections of the spinal cord, as demonstrated by the reviewed animal studies on spinaliza Read More

In this review we will first give a historical account of how the discovery of persistent inward currents (PICs) and plateau potentials changed the understanding of the operation and function of the “final common path”, i.e. the motoneurons themselves. A major function of voltage-dependent PICs is to serve as an adjustable amplifier of classical synaptic inputs. The complex control of this, and other intrinsic properties, certainl Read More

Serotonin (5-HT) is one of the main transmitters in the nervous system. Serotonergic neurons in the raphe nuclei in the brainstem innervate most parts of the central nervous system including motoneurons in the spinal cord and brainstem. This review will focus on the modulatory role that 5-HT exerts on motoneurons and its physiological consequences. The somato-dendritic compartments of motoneurons are densely innervate Read More

For many years, glial cells from the central nervous system have been considered as support cells involved in the homeostasis of the brain. However, a series of key-findings obtained during the past two decades has put light on unexpected roles for glia and it is getting more and more admitted that glia play an active role in several physiological functions. The discovery that a bidirectional communication takes place bet Read More

Spinal cord injury (SCI) often results in permanent paralysis because there is little spontaneous repair. Neuronal injury in the central nervous system (CNS) causes breakage of axonal connections, release of myelin, inflammation and cell death at the lesion site. Many factors contribute to the failure of spontaneous repair after SCI, including the presence of growth inhibitory proteins in myelin, the inflammatory environment of Read More

Several motor behaviors such as locomotion, respiration, sexual function, and micturition are generated by rhythmic and stereotyped motor patterns of activity. In most cases, these functions are primarily controlled by signals and neuronal commands that originate from the brainstem and spinal cord. Defined as the storage and periodic elimination of urine, micturition requires a complex neural control system that coor Read More

Although research on neural tissue repair has made enormous progress in recent years, spinal cord injury remains a devastating condition for which there is still no cure. In fact, recent estimates of prevalence in the United States reveal that spinal cord injury has undergone a five-fold increase in the last decades. Though, it has become the second most common neurological problem in North America after Alzheimer’s Read More

Most animal models of contused, compressed or transected spinal cord injury (SCI) require a laminectomy to be performed. However, despite advantages and disadvantages associated with each of these models, the laminectomy itself is generally associated with significant problems including longer surgery and anaesthesia (related post-operative complications), neuropathic pain, spinal instabilities, deformities, lordos Read More

In 1966, Shik, Severin and Orlovskii discovered that electrical stimulation of a region at the junction between the midbrain and hindbrain elicited controlled walking and running in the cat. The region was named Mesencephalic Locomotor Region (MLR). Since then, this locomotor center was shown to control locomotion in various vertebrate species, including the lamprey, salamander, stingray, rat, guinea-pig, rabbit or monke Read More

Much like locomotion or micturition, respiration is a rhythmic and stereotyped motor pattern controlled mainly by non-cortical structures including a complex circuit in the brainstem. Because tight regulation of lung ventilation is essential from the beginning of life, it has been presumed that the neural system regulating breathing is fixed, following a genetically predetermined developmental pattern. Here, we review evidence indi Read More

γ-aminobutyric acid (GABA) plays many of its key roles in embryonic development and functioning of the central nervous system (CNS) by acting on ligand gated chloride-permeable channels known as GABAA receptors (GABAAR). Classically, GABAARmediated synaptic communication is tailored to allow rapid and precise transmission of information to synchronize the activity of large populations of cells to generate and maintain Read More

Throughout life, neuronal network properties are modulated according to both external and internal stimuli. These adaptive capabilities of the central nervous system (CNS) have been generically termed “plasticity”. One prominent form of CNS plasticity is the capability of synapses to change their strength. Synaptic strength is not a constant value but depends at each moment on the synapse’s past activity. These chan Read More

Synaptic transmission through descending motor pathways to lumbar motoneurons and then to leg muscles is essential for walking in humans and rats. Spinal cord injury (SCI), even when incomplete, results in diminished transmission to motoneurons and very limited recovery of motor function. Neurotrophins have emerged as essential molecules known to promote cell survival and support anatomical reorganization in Read More